Fix qty validation and custom option buy request provider

Author: pmclain

app/code/Magento/QuoteGraphQl/Model/Cart/BuyRequest/CustomizableOptionsDataProvider.php

@@ -44,7 +44,7 @@ public function execute(array $cartItemData): array
             }
         }
 
-        return ['options' => $customizableOptionsData];
+        return ['options' => $customizableOptions];
     }
 
     /**

app/code/Magento/QuoteGraphQl/Model/Cart/BuyRequest/QuantityDataProvider.php

@@ -38,7 +38,14 @@ public function execute(array $cartItemData): array
         if (!isset($qty)) {
             throw new GraphQlInputException(__('Missing key "quantity" in cart item data'));
         }
+        $qty = (float)$qty;
 
-        return ['qty' => (float)$qty];
+        if ($qty <= 0) {
+            throw new GraphQlInputException(
+                __('Please enter a number greater than 0 in this field.')
+            );
+        }
+
+        return ['qty' => $qty];
     }
 }